Trivaric acid, a potent depside human leukocyte elastase inhibitor

Area of Science:

• Natural Product Chemistry
• Enzymology
• Pharmacology

Background:

• Human leukocyte elastase (HLE) is a serine protease linked to inflammatory diseases.
• HLE is a significant therapeutic target for anti-inflammatory drug development.

Purpose of the Study:

• To identify novel inhibitors of human leukocyte elastase from fungal metabolites.
• To characterize the inhibitory activity and selectivity of isolated depsides.

Main Methods:

• Isolation of depsides (nordivaricatic acid, divarinyl divarate, trivaric acid) from a soil-derived fungal strain.
• Enzyme inhibition assays to determine IC50 and Ki values for HLE inhibition.
• Kinetic studies to elucidate the inhibition mechanism.
• Selectivity profiling against other serine proteases (chymotrypsin, trypsin, thrombin).

Main Results:

• Trivaric acid demonstrated potent, reversible, competitive inhibition of HLE with an IC50 of 1.8 µM and Ki of 0.6 µM.
• Nordivaricatic acid and divarinyl divarate showed only weak inhibitory activity against HLE.
• The isolated depsides exhibited no significant inhibition against chymotrypsin, trypsin, or thrombin at 150 µM.

Conclusions:

• Trivaric acid is a potent and selective inhibitor of human leukocyte elastase.
• Fungal depsides represent a promising class of compounds for HLE-targeted anti-inflammatory drug discovery.